Firstly, I bloody hate this term, it is only ever used for women, it is mysogynistic and ageist.
However - I don't ever want to be seen as one. I had a day out yesterday with my teen dd and we had really awful service in Pizza express, a 45 min wait for food and then they forgot part of the order and the waitress was not rude exactly, but sort of snippy. despite me being friendly and smiley as possible as I know its a hard job.
But the worry I would be seen as a karen was what stopped me complaining. I already feel like younger people see me in a negative way now I am past 40 and this karen shit makes it worse.